1. Field
Embodiments relate to an organic light emitting diode (OLED) display device and a method of fabricating the same.
2. Description of the Related Art
In general, polysilicon layers have advantages including, e.g., high field effect mobility, applicability to high speed circuits, and enablement of complementary metal-oxide semiconductor (CMOS) circuit constitution. Thus, polysilicon layers are widely used for semiconductor layers for TFTs. TFTs using these polysilicon layers are mainly used for active devices of active matrix liquid crystal displays (AMLCDs) and switching devices and driving devices of OLEDs.
Methods of crystallizing amorphous silicon into polysilicon may include, e.g., solid phase crystallization (SPC), excimer laser crystallization (ELS), metal induced crystallization (MIC), metal induced lateral crystallization (MILC), etc.
While the polysilicon layer formed through crystallization using a laser may be advantageous to produce a driving TFT or a switching TFT in an OLED, production of the polysilicon layer may incur a large cost and it may not be readily applied to a large-sized display.
Because of the difficulty in application of the large-sized display, crystallization methods not using a laser are being actively researched.
While a polysilicon layer formed through SPC may have a uniform grain size, the grain size may be too small.
MIC, MILC, and super grain silicon (SGS) crystallization, etc., using a metal catalyst may generate a polysilicon layer having a large grain size.